In order to study the effects of soil properties，potato yield and quality under nitrogen reduction with carbon-based fertilizer，a field experiment was designed with following treatments in Northeast Yunnan，no nitrogen fertilizer(CK)，conventional nitrogen fertilizer(N100)，80% nitrogen fertilizer + 1500 kg/hm² carbon-based fertilizer(N80BC1)，80% nitrogen fertilizer + 3000 kg/hm² carbon-based fertilizer(N80BC2)，60% nitrogen fertilizer + 1500 kg/hm² carbon-based fertilizer(N60BC1)，60% nitrogen fertilizer + 3000 kg/hm²(N60BC2). The results showed that with the application of biochar-based fertilizer，soil pH，organic matter and total nitrogen content increased by 1.5%-15.7%，5.7%-46.3% and 14.6%-24.4%，respectively，compared to that of the N100 treatment. With increasing rates of biochar-based fertilizer，soil pH，organic matter，total nitrogen，total phosphorus and total potassium，alkali hydrolyzable nitrogen and available potassium increased except for available phosphorus. The application of carbon-based fertilizer increased soil urease and catalase，and the N80BC2 treatments significantly increased the activities of soil urease by 31.26% and catalase 31.18%. However，the activities of sucrase decreased significantly with the increase of carbon-based fertilizer. Carbon-based fertilizer also increased the content of nitrogen and phosphorus nutrients in potato tubers. Biochar and nitrogen fertilizer combined application also increased potato yield，soluble sugar，starch，protein and vitamin C content，and the yield(33.33 t/hm²) of N80BC2 treatment was the highest，which increased by 6.67 t/hm² and 25.0%，compared with N100 treatment. The correlation analysis showed that there was a significant positive correlation between soil pH，total phosphorus and potassium contents，catalase and urease activities and potato yield and quality. The application of nitrogen reduction combined with carbon-based fertilizer could effectively improve soil acidity，increase soil nutrient content and enzyme activity，promote nutrient transformation，increase plant nutrient content，and improve potato yield，quality and economic efficiency，with the N80BC2 treatment being the most effective.